Multiple-wheel drive



May 14, 1929 J. R. vJUNKIN MULTIPLE WHEEL DRIVE 2 Sheets-Sheet Filed NOV. l, 1927 May 14, 1929.

J. R. JUNKIN 1,713,133

MULTIPLE WHEEL DRIVE Filed Nov. l,

2 Sheets-Sheet 2 Patented May 14, 1929.

lUNITED STATES JOHN B. JUNXIN, F SIERRA MADRE, CALIFORNIA.

ilumina-WHEEL parvis.

Application led November 1, 1927. Seriallo. 230,250.

This invention relates to multiple wheel drives as commonly applied to motor vehicles in the form of four wheel drives, the main object of such four wheel drives being to decrease the load per unit of area on the roadway or, in other words, the distribution of the load over a reater surface. n

An object o the present invention is to provide a construction that may be readily substituted for the two wheel drive with which many motor vehicles are at present equipped. When the invention is to be installed as an attachment to existing two wheel drive motor vehicles, the entire rear axle assembly is removed together with the Wheels driven thereby and this invention is substituted therefor as it includes a rear axle and differential.

Another obj ect of the invention is strength and simplicity of construction.

Another object is to provide an attachment of this character that will function the same as though the -vehicle were originally equipped with the'invention.

Another object is to provide in an economical way for a differential drive between each pair of wheels and the axle so that when the tires become worn to unequal diameters, differential motion can occur between those that are mounted on the wheels of one pair.

Other objects and advantages will appear l in the subjoined detailed description.

The accompanying drawings illustrate the invention.

Fig. 1 is a plan view, partly in section, of a multiple wheel drive constructed in accordance with the provisions of thisinvention, a fragment of a chassis frame and a propeller shaft being indicated also in 'broken lines.

Fig. 2 is an elevation, partly in section, from the line indicated by 2-2 Fig. 1.

Fig. 3 is an enlarged sectional detail of one of the diferentialgearings.

Fig. 4 is an elevation, partly in section, from the line indicated by 4-4, Fig. 3.

Fig. 5 is a plan view showing a modification of the drive connections between the'axle and the wheels.

A fragment of the motor vehicle frame 1s indicated at A and a fragment ofthe propeller shaft is indicated at B. The frame A is provided with the usual resilient suspension means indicated at C, said means in this instance being leaf springs and the necessary shackles. These parts may be of an well known or approved construction an need not be described more in detail herein. The suspension means C are attached to and support a housing comprising tubular end portions 6 and an enlarged intermediate differential gear case 7. The housing portions 6, 7 may be of integral construction or otherwise, as desired. Each tubular housing portion 6.1s provided internally near its outer end with the bearing 8 and at its inner end with the bearing 9 and mounted in each set of bearings 8, 9 is a tubular member 10. The tubular members 10 are held against endwise movement outwardly by nuts 11 which are screwed. onto the inner end portionsI of the tubular members 10 vand thrust against the inner ends of the bearings 9. The tubular members 10 constitute the pivots of rocker arms 12 which are secured in any suitable manner to the members 10.

Oii the end portions of each rocker arm 12 are rotatably mounted drive wheels 13.

The wheels 13 are preferably mounted so that they can be adjusted toward and from one another for a purpose to be made clear hereinafter and, for this reason, the stub axles 14 of the wheels 13 are provided near their inner ends with eccentrics 15 which are mounted to turn in split bearings 16 on the end portions of the rocker arms 12. Each split bearing 16 is provided on opposite sides of its kerf 17 with ears 18 through which pass bolts 19 for the purpose of tightening the bearing upon the eccentric. By turning the eccentrics 15, it is clear that the associated stub axles will be moved toward or from one another, thus moving the associated wheels 13 closer together or farther apart.

In order to readily turn the eccentrics 15. the stub axles 14 are provided at their inner ends with wrenchl seats 20 which, in the present instance, are shown of hexagonal shape. To further secure the eccentrics 15 against turning in the bearings 16, it is preferable to permanently engage each of the wrench seats with a wrench 21. Each wrench 21 may be secured against turning by a cap screw or bolt 22 which selectively engages one of a number of holes 23 in the associated rocker arm 12. When it is desired to shift one of the wheels 13, the bolt 22 will be removed and the wrench 21 turned to cause turning of the eccentric 15. When such turn'- ing of the wrench 21 removes its outer end a distance from any of the holes 23, said wrench may be slipped off of the wrench seat and then returnedto the wrench seat in a posij lll titl

tion to permit the bolt 22 to engage in one ot the holes 23. Thus, the Wrenches 2l serve the double purpose of turning the eccentrics and positively holding said eccentrics against turning after said cccentrics have been adjusted to the desired position.

lVithin the enlarged housing portion 7 is a differential gearing. indicated in gener l by the character 24. 'lhis diilerential gearing may be ont the usual or any preferred type and is driven by the propeller shaft B through pinion 25 on the propeller shaft and a ring gear 26 constituting a portion oi the diiler gearing 24.

Thedil'ierential gearing 2l connectstlietwo halves 2'? an axle. The axle halves 27 extend through the tubular members 10 and are rotatably supported near their outer ends in the tubular members 1() by bearings 28 which are carried by the tubular members 10. The axle halves 27 project beyond the outer faces of the rocher arms 12 and are connected by any suitable gearing with the wheels 13.

For illustrative purposes only, I have shown in the drawings several types of gearing for connecting the axle halves 27 with the wheels 13. For example, in Fig. 1 of the drawings the axle halves 27 are each provided with sprocket wheels 29 and the sprocket wheels 29 drive sprocket chains 30 which respectively engage other sprocket Wheels 31 mounted on or connected vvith the drive wheels i3.

In Fig. 5 there is disclosed another type of gearing for connecting the shaft halves 27 with the vvheels 13. In Fig. 5 the elements that functionally correspond to those illustrated ir. Fig. 1 are indicated by the same reference characters with the addition of the letter af ln this instance, the axle hall 273L is provided with spur pinions 32 which drive idler spur gears 33, rotatably mounted at 34 on the rocker arm 12a. The idler spur gears 33 are in mesh With spur gears 35 which are secured to or connected with the respective drive Wheels 13a. From. this itvvill be seen that any suitable form olf gearing may be employed tor operatively connecting the axle with the drive wheels.

While it is .possible to employ but the one did'erential gearing 24s, it isprelierable to employ other diderential gearings, one suc'n gearing between each pair oi associated drive Wheels 13 and, accordingly, instead ol lining the sprocket Wheels 29* 'to the shalt halves 27, l prefer to rotatably mount said sprocket Wheels 29 on the axle =calves 27 and to connect the associated sproclret vvheels 29, in each instance, by a dierential gearing T,vhich is indicated in general by character 36. This construction muy be clearly seen in ligs. 3 and d where the spider 37 of the differential gearing is keyed or otheravise secured at 38 to the axle hall 27." and said spider carries bevel plnions 39 in mesh imams with level gears l() constructed integral with or secured in any suitable manner to the sprocket wheels 29.

'lhe invention operates follows:

rlhe propeller shalt B, being driven by 'the prime mover in a manner Well understood in this art, operates the axle halves 27 through the dillerential gearing 2l; and the axle halves 27, through the differential gearings IMS and driving cmincctious between said differential gearings 36 and vvheels 13, edect driving oiE said Wheels. In the construction illustrated in lig. 1 the driving connections, as have been hereinbctorc described, comH prise the sprocket wheels 2l), di tl'erential gearings 3G, sprocket wheels 30 and sprocket wheels ill, and in Fig. 5 these connections comprise the gear wheels 32, 33, 35 and dii'- ferential gearing 36a. lvl/'hen the vehicle is steered to the right or left, the diderential gearing 2l compensates *lor the dierences in the distance traveled by the pairs or wheels on opposite sides oli the vehicle, in a manner well understood in this art. 'lhe differential gearing 2l also compensates for diderent speeds ot the pairs ci wheels on opposite sides of the vehicle due to any diderence in diameters the tires o the wheels.

Each oit the diderential gearings 36 compensates Jlor dillerences in rim travel oit the associated Wheels 13 resulting from a dili'erence in diameters o the tires of said Wheels or from any inequalities in the surface of the roadway upon which said tires are running.

I claim:

1. A multiple `Wheel drive comprising a housing, a differential gearing in the housing, rocker arms provided with tubular members oscillatably mounted in said housing, axle members connected at their inner ends with the differential gearing and rotatably mounted in the tubular members and proiecting beyond the rocker arms, power transmitting members associated vvith each axle member, and a dierential gearing operably connecting each axle member vvith the power transmitting member associated thcrevvitli.

2. A multiple Wheel drive comprising a housing, a diderential gearing in the housing, rocker arms provided with tabular members oscillatably mounted in said housing, axle members connected at their inner ends with the differential gearing and rotatably mounted in the tubular members and projecting be youd the rocker arms, Wheels rotatably mounted on each or? rocher arms, and driving connections connecting each axle member to the Wheels associated vvith one oit the rocker arms, each olf said driving connections including a diderential gearing.

3. .l multiple 'wheel drive comprising a housing, a diiierential gearing in the housing, rocher arms. provided with tubular escillatably mounted in erle members rotatably mounted in the tubular members and connected at their inner ends with the differential gearing and projecting through the rocker arms, a. spider secured to the outer end of each axle member, a .pair of gears rotatably mounted on each axle member, pinions carried by each spider and meshing with the associated pair of gears,

a vehicle frame, a. mea-ns supporting the` 10 frame on the tubular members, wheels rotatabIy mounted on the opposite'ends of each speeds of the wheels associated with either 15 rocker arm.

Signed at Los Angeles, Calif., this 17 day of October, 1927.

JOHN R.IJUNK1N. 

